The invention relates to a crankcase ventilation system for motor vehicles, in which the crankcase gases are returned from the cylinder block and crankcase into an intake system of an internal-combustion engine via a main ventilation system or a safety ventilation system. Connecting pieces are arranged at an air guiding housing of the intake system for connecting lines of the main ventilation system and of the safety ventilation system.
In the case of a known crankcase ventilation system (Service Information 1985, Porsche 928 S, USA, Pages 30 and 31) of the initially mentioned type, two connecting pieces arranged at a spacing from one another are provided at the air guiding housing of the intake system, one connecting piece being connected with the line of the main ventilation system and the other connecting piece being connected with the line of the safety ventilation system. This crankcase ventilation system functions well, but the construction of the air guiding housing with the two connecting pieces is costly. In addition, the two connecting pieces require considerable space at the air guiding housing so that the narrow space conditions that anyhow are present particularly in the area of the intake system of a four-valve engine are limited even more.
It is an objective of the invention to take such measures at a crankcase ventilation system that the connection between the lines of the two systems and the air guiding housing is simplified with respect to construction and also requires little space.
According to the invention, this objective is achieved by providing a common connecting piece that connects both crankcase ventilation systems with the air guide housing. In certain preferred embodiments, the common connecting piece has outlet openings to the air guide housing that are spaced from one another in the vented gas flow direction. The preferred embodiments of the invention have a unitary connecting piece with a Y-shape, the arms of the y connecting respectively to the two ventilation systems.
The main advantages achieved by means of the invention are that by the arrangement of only one connecting piece for the lines of both systems, a simple and space-saving connection is established between the lines and the air guiding housing. By means of the separate ducts inside the connecting piece for the two systems and the outlet openings that are offset with respect to one another, a good functioning of the crankcase ventilation system is achieved. When the outlet opening of the main ventilation system is, for example, closed by ice, the safety ventilation system with the outlet opening that in sections projects into the inside of the air guiding housing will take over the crankcase ventilation until the closed connection of the main ventilation system in the air guiding housing has become penetrable again after the engine operating temperature or a sufficient engine compartment temperature has been reached. The connecting piece can be constructed in an easy and cost-effective way. Because of the locking connection between the connecting piece and the short pipe section of the air guiding housing in certain preferred embodiments, a rapid and easy mounting of the connecting piece is ensured.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.